JPS6365751B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a thermal spray material, and particularly to a light brown ceramic thermal spray material that has a beautiful thermal spray coating and is stable and does not discolor or fade.

[Prior Art] The enameling method, which is conventionally known as a coloring coating technique for the surface of a substrate, has the disadvantage that it cannot be applied to concrete, wood, etc. because it heats the substrate.

The thermal spraying method that improves this drawback can coat the surface of the substrate without changing the properties of the substrate, and by using ceramics as the thermal spraying material, it has the advantage of imparting heat resistance, corrosion resistance, abrasion resistance, etc. to the coating. .

Thermal spray materials are required to have properties such as heat resistance, corrosion resistance, and abrasion resistance depending on their purpose. If the purpose is to coat the surface of building materials etc., particularly high heat resistance is not required, and if used for interior materials etc., corrosion resistance will not be much of a problem. Instead, color tone becomes an important element. In addition, it must not discolor for a long period of time, and if it is used in places that are prone to wear, it must have hardness, wear resistance, etc.

Traditionally, thermal spray coating materials with decorative properties that give a beautiful appearance include black Al ₂ O ₃ /TiO ₂ and white
Al ₂ O ₃ , Al ₂ O ₃・C ₀ O exhibiting cobalt blue color
etc. are known, but their number is small.

The reason why there is so little colored thermal spray material is due to the fact that the color tone of the thermal spray material before and after thermal spraying is not necessarily the same. In particular, when thermal spraying ceramics is carried out using the plasma method, plasma is generated in a reducing atmosphere, so there are more oxygen vacancies than in a normal crystal lattice state, which causes color absorption, which causes problems after thermal spraying. It is believed that the overall color tone of the ceramic coating will be different from the color tone of the ceramic before spraying. Therefore, it is extremely difficult to predict the color tone obtained as a result of thermal spraying from the apparent color tone of the thermal spraying material before thermal spraying, and it is often unknown until thermal spraying is actually performed.

However, when performing thermal spraying, it is important to predict the color tone of the thermal spray coating before thermal spraying and to develop a thermal spray material that matches the desired color tone.

It is well known that each metal oxide generally has a unique color. For example, beryllium oxide BeO itself is white;
When a compound is made with Al ₂ O ₃ , SiO _{2 ,} etc., for example, 3BeO.Al _{2 O} 3.6SiO ₂ , which has the composition of beryl, exhibits the pale green color of beryl. In addition, MnO itself exhibits a green color, which is similar to CaO.
It also appears green when it forms a compound with SiO ₂ etc.
Saphire, known as a natural and man-made gemstone,
Ruby, spinel, quartz, amethyst, etc. are all due to the unique coloring of the metal oxides that are their compositional components.

However, thermal spray materials are generally sprayed at high temperatures. Moreover, when the thermal spraying material is, for example, a mixture or compound of one or more metal oxides, when these materials are subjected to high-temperature thermal spraying, particularly plasma spraying, as mentioned above, a part of the composition may suffer from oxygen vacancies at the high temperature of the plasma. The color tone of the thermal spray material before thermal spraying is often different from the color tone after it is thermally sprayed.

[Objective of the Invention] In view of the above-mentioned problems of thermal spraying technology, the present invention has been developed to provide a light brown coating material that does not damage the base material to be thermally sprayed, has sufficient hardness, toughness, and abrasion resistance as a thermal spray coating for building materials, etc. The purpose of the present invention is to provide a ceramic thermal spray material that develops color.

[Structure of the Invention] The ceramic spray material of the present invention has a novel composition consisting of _MnO2 : 1 _to 20% by weight, _SiO2 : 10 to 30% by weight, and _Al2O3 : 50 to 80% by weight.

Al ₂ O ₃ is a material with excellent heat resistance, high hardness, and wear resistance, but its thermal spray coating is white. The present invention utilizes the properties of Al ₂ O ₃ , and the above composition and range were selected in order to obtain a thermally sprayed coating that develops a light brown color and to provide sufficient hardness, toughness, and abrasion resistance. be.

MnO ₂ is a component that develops a light brown color, and as its content is increased from 1% by weight to 20% by weight, the color can be gradually increased from light brown to almost brown.

SiO ₂ gives toughness to the sprayed coating, and is suitably used in an amount of 10 to 30% by weight in relation to the remaining components.

If Al ₂ O ₃ is less than 50% by weight, it will lack hardness.
The wear resistance of the sprayed coating is increased. Furthermore, the upper limit is limited to 90% due to the amounts of MnO ₂ and SiO ₂ .

The thermal spraying material of the present invention has a component composition of MnO ₂ ,
It can be used in any of the following forms: a mixture of SiO ₂ and Al ₂ O ₃ as individual substances, a granulated product granulated with a binder, or a granulated product obtained by melting, solidifying and pulverizing the mixture. can.

[Effects of the Invention] The present thermal spraying material not only has a decorative effect that gives a sense of beauty to objects to be thermally sprayed, particularly buildings made of wood and concrete, but also is strong and has practically sufficient hardness and abrasion resistance.

[Example] 5% by weight of dark black electrolytic manzene dioxide (MnO ₂ ) powder, 25% by weight of white SiO ₂ powder, 70% by weight of white Al ₂ O ₃ powder
The thermal spray material, which is uniformly mixed in weight percent, is a blackish brown powder before thermal spraying. As a result of plasma spraying this thermal spraying material onto a concrete base material, the coated sprayed surface was given a light brown, calm and beautiful appearance. The characteristics of this sprayed surface are as follows.

Although quantitative values are not listed for toughness,
Qualitative observation clearly showed that the toughness was high.

It was also demonstrated that the sprayed coating did not change color or fade even after three years and was extremely stable.

The hardness shown below is obtained by mirror polishing the sprayed coating surface.
Microvitkers hardness was measured under the conditions of a load of 100 g and a holding time of 15 seconds.

The wear rate was determined by projecting an abrasive onto the thermally sprayed coating using a sandblasting method and measuring the weight loss of the coated surface at that time. The blasting device used was that disclosed in Japanese Patent Application Laid-Open No. 51-6892. Alumina abrasive grains (particle size
JIS#24), projection amount 32Kg/min, projection speed
2500m/min, projection angle 30°, feeding speed of coated sample
It was blasted at a rate of 0.75m/min and a projection distance of 400mm.

Hardness Hv (100) 680-800 Wear rate 0.032 (g/cm ² ) As a comparative value, if Al ₂ O ₃ · TiO ₂ (40% by weight of TiO ₂ ), which is generally used as a thermal spray material, is shown, the thermal spray coating will be Hardness Hv (100) is 700-1000, wear rate is
It is 0.021 (g/cm ² ). However, this thermal spray coating is black and has a narrow application range.

The thermal sprayed material of the present invention does not have much difference compared to this comparative value, and the toughness of the material of the present invention is actually superior. Moreover, because it develops a light brown color, it is in high demand as a thermal spraying material for building materials, etc.

Claims (1)

[Claims] 1 Manganese dioxide (MnO ₂ ) 1-20% by weight, silica (SiO ₂ ) 10-30% by weight, alumina (Al ₂ O ₃ )
Ceramic sprayed material consisting of 50-80% by weight.